Let-off mechanism for looms.



1. wARuR0N.` LET-OFF MECHANISM FOR LUOMS.

APPLICATION EILED FEB. 1.6. 19th 1,245,290. mma Nov. 6, 1917.

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I. wAIIBURmN.

LET-OFF MECHANISM FOR LOOMS. APPLICATION FILED FEB. I6. |911.

1 ,245,2901, I Patented Nov. 6,1917'.

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1,245,290. Patented Nov. 6, 191?.

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UNITED STATES PATENT oEEicE.

J CHN WABBUBTON, 0F PATTERSON, NEW JERSEY, ASSIGN-'R 0F ONE-HALF T0DANIEL WARD, 0l' PATEBSQN, NEW JERSEY.

i A LET-OFF MECHAN'ISM 'FOB LOOKS.

pecication of Letters Patent.

Application led February 18, 1917. Serial No. 148,967.

To all whom z't may concern:

Be it known that I, JOHN WARBUETON, a citizen of the United States,residin at Paterson, in the county of Passaic and tate of New Jersey,have invented certain new and useful lmprovementsin Let-Off Mechanismsfor Looms, of which the following is a specification.

This invention relates to means for controlling the advance undertension of the :cloth and warp in a loom, and it has referenceparticularly to the so-called let-0H part of such means. I seek by thisinvention principally to obtain an equable tension on the warp under allconditions. For attaining this object the commonly employed expedientinvolves ropes or chains wound on the let-oli warp-supply beam and heldtight by Weights, which are varied to suit the character of the goodsbeing woven and other conditions. But, especially where the weightsrequire to be heavy, such means develops failure to produce the desiredcondition of absolute constancy of tension; for instance, if ropes areemployed, they will exert diiierent degrees of resistance to rotation ofthe beam according as they absorb more or less humidity from theatmosphere; in any case, such means is unreliable, the action of thebeam beine' alternate dwells and slips, which lead to shiers (2. e.,undue spacing of the weft and other imperfections in the cloth.

My invention contemplates a novel combination of parts whereby, givenmeans to take up the warp at a denite rate of advance,

the warp is let oi at a rate different from that at which it is taken upand is at the -same time held taut,the part of the combination whichcauses the warp to be held taut governing the part which eEects theletting oif so that from time to time the difference between the rate ofletting oi and the rate of taking up is compensated for; in theconstruction herein shown and described 'by way of illustration, thewfarp is let ofi faster than it is taken up, and the com ensationinvolves stopping the let-off actlon from time to'time while the take-upcontinues.

In the accompanying drawings, in which Figure l is a side elevation of aloom embodying my invention; K

Fig. 2 is a rear elevation of the improved mechanism;

Fig, 3 is a side elevation, partlyin sectlon;

4r is a plan view; l

Fig. 5 1s a plan view like Fig. d excepting that the arts are in theposition that they occupy w en the warp is let back;

F1g. 6 is an inside elevation of a fragment of pawl 'w and its actuatinglever; and,

Fig. 7 is a sectional view 'on the line 7 7 of Fig. 5.

. ln the loom frame a there are a take-up means a hatten structure cequipped with a reed @Z and a shuttle or shuttles and picklng mechanismtherefor (not shown); and means e to drive the take-up mechanism at adeiinite take-up rate.

Two stands f form a rearwardly projecting part of the frame a. They acrda bearlng for a shaft g having keyed thereto two upwardly proJectingarms z.,-in which is lournaled the warp-supply or let-od beam @,-and arearwardly projecting arm j; parts g, It and j form in eiiect a ll-cranklever.

J ournaled in frame a are two bell-crank levers equipped with weightsZand connected with the trunnions links fm., so that levers g-ib-j andthe levers la move 'together` on their respective fulcra.

There is a ratchet wheel o journaled on shaft g, and a system ofgearingp, g r and c connectlng the ratchet wheel with the beam, themember p of such gearing being fast with the ratchet wheel, the membersPatented Nov. 6, 1917.

of the beam by g-Jr thereof fixed to rotate together on a .the idle endof the pawl and adapted to retract it when the lever swings to the left.For actuating pawl w there is ulcrumed in bar u another lever y adaptedto strike a lug fw on pawl fw when the lever swings to the right andretract the pawl. The levers arey connected by a link e so as to swingtogether on their ulcra, and they are made a golng part of the loom bybeing connected i with a crankc on the'batten structure e by a pitman 2.There is thus produced an escapement means which, with the levers y keptoscillating and assuming there is a rotating influence belng exerted onthe ratchet wheel, results in the ratchet wheel and hence the beamrotating step by step in the direction to deliver the warp; the partsare timed so that the rate of delivery of the warp is different fromthat of its taking up by the take-up mechanism, in the present case at afaster rate. The fulcrumvof the lever y is a stud 3 (as shown, also theivot for pawl lw) and the lever is shiftable t ereon by virtue ofa sloty which receives it and allows the lever to descend to a position whereinstead of continuing to strike the pawl a recess y2 formed therein willoppose the lug w on the pawl 'and the pawl will remain unretracted.Lever y is carried by a stirrup piece 4 which is pivotallypendent fromarm j and has its lower end turned oif and penetrated by a rod 5 andinterposed between two springs 6 coiled around lever, which support therod (Figs. 6 and 7).

Assume the position of the parts to be as shown in Fi 3, and the loom tobe stopped: The freely iftable means g, 1' and i, under the pressure ofthe train of parts Z, k, m, h, g and y' is exerting a tauteninginfluence on warp A, the beam i beln held against rotation to unwind thewar ecause geared with the ratchet wheel, which is locked by one of thepawls. If the loom be now started, the pawls will free the ratchet wheelstep by step at a faster rate than the warp 1s taken up, in consequenceof vwhich the means Z, la, m, h g and 7' will lforce the beam back,which wi depress the lever y until nally its recess y2 opposes the lugw', so

that the lever will cease to withdraw the pawl fw; this hiatus in theretracting movements of the pawl may endure for one or more oscillationsof t e levers, but since pawl fw remains holding the ratchet wheel andonly pawl fv continues in motion, it will terminate as soon as the takeup means has returned the beam forward and consequently elevated thelever y to the position where it will again actuate pawl w, whereuponthe warp will again be delivered at a rate in excess of its taking up,and so on. It will be observed that always the tension remainsabsolutely equable.

If it should be necessary toadvance the warp for any purpose to bringthe fell of the cloth forward of its normal position (indicated by arrowB in Fig. 1), or if due to a smash it be forced forward, or if it isnecessary to let back the warp, the abnormal movement of stirrup 4incident thereto is taken up by one or the other of the s rings 6. Aumethe warp to be advanced, or instance, so as to leavea cut-olf mark inthe the rodbetween two lugs 7 on thetion of said beam includin cloth bykabsence of filling, the parts h, j 4would be tilted forward, which w0u lcompress upper spring 6; the mechanism, on being now set in motion,would dellver the warp at a rate exceeding its taking up until saidsprin became restored to normal condition an the lever y thereupon fallssuficiently to clear the pawl w and cease to actuate it. Conversely,assume the warp to be let back (Fig. 5), lower sprin 6 would becompressed; on setting the mec anism in motion, since pawl 'w is nowidle due to lug lw of pawl w being opposed to it, the beam remains heldagainst rotation until the takeup, through the warp, has drawn itforward and consequently elevated lever y to such position that invibrating it will again put pawl w in motion.

I do not wish to be limited to the details of construction herein setforth, what I claim being:

1. In combination, with a take-up mechanism, a let-off mechanismincluding a freely shiftable warp-tautening rotary warp-supply beam andmeans, controlled by the shifting beam, for controlling the letting-offrotation of the beam, said means including a rotary element connected torotate with ,the beam and a going ste -by-step means controlling therotation o said element.

2. In combination, with a take-up mechanism, a let-off mechanismincluding a freely shiftable warp-tautening rotary warp-sugiply beam andmeans, controlled by the shi ing beam, for controlling the letting-offrotation of the beam, said means including a Y rotary element connectedto rotate with the beam, a pair of check devices movable into and out ofand normally held in checking relation to said element, and separategoing instrumentalities to impart retracting movement to each of saiddevices.

3. -In combination, with a take-up mechanism, a let-olf mechanismincluding a shiftable fulcrumed warp-tautening structure having awarp-rotated beam, and means, controlled by the shifting fulcrumedstructure, for controlling the rotation of said beam including a rotaryelement connected to rotate with the beam and a going stepby-step meanscontrolling the rotation of said element.

4. In combination, with a take-up mechanism, a let-off mechanismincluding 'a shiftable fulcrumed` warp-tautening structure having awarp-rotated warp-supply beam,

and means, controlled by the shifting fulcrumed structure, forcontrolling the rotaa rotary element connected to rotate wit the beamand a going step-by-step means controlling the rotation of said element.

5. In combination, with a take-up mechanism, a let-off mechanismincluding a shiftable ,fulcrumed warp-tautening structure having awarp-rotated beam, and means,

controlled by the shifting fulcrumed structure, for controlling therotation of said beam including a rotary element journaled concentricwith the fulcrum of said structure and connected to rotate with the beamand a going step-by-step means controlling the rotation of said element.

6. In combination, with a take-up mechanism, a let-oil' mechanismincluding a shiftable, fulcrumed Warp-tautening structure having aWarp-rotated Warp-supply beam, and means, controlled by the shiftingfulcrumed structure, for controlling the rotation of said beam includina rotary element journaled concentric Wlth the fulcrum of said structureandv connected to .rotate with the beam and a going step-by-step meanscontrolling the rotation of said element. Y

7. In combination, With the frame, a take up mechanism arranged thereinand a letoff mechanism including a shiftable upstanding Warp-tauteningstructure having a Warp-rotated beam and ulcrumed in the frame with itsaxis parallel to the beam, means normally acting to move said structurerelatively away from the take-up mechanism, and means, controlled by theshifting Warp-tautening structure, to control the rota-tion of the beam.

8. In combination, with the frame, a takeup mechanism arranged thereinand a leto" mechanism including a shiftable upstanding Warp tauteningstructure having a Warp-rotated beam and fulcrumed in the frame with itsaxis parallel to the beam, a rotary element journaled in the frameconcentric with said axis and connected to rotate with the beam, andmeans, controlled by the shifting Warp-tautening structure, to controlthe rotation of said element.

In testimony whereof I aiix m si ature.

JOI-IN WARB IIFON.

